Identifying effective strategies for treating obesity is both a clinical challenge and a public health priority. Over 70% of the U.S. population is overweight or obese, and obesity in nniddle age translates into higher rates of hospitalization. Medicare expenditures, disability, and mortality risk among older adults. While a variety of approaches are successful in achieving initial weight loss, techniques for maintenance of initial weight loss have largely been unsuccessful. This 3- arm randomized controlled trial will compare the relative effectiveness and cost-effectiveness of (1) lottery-based incentives, (2) traditional direct payments, and (3) daily feedback without incentives among patients who successfully lost at least 5 kg over 6 months during participation in Weight Watchers (Pre Phase), incentives will be provided to some study participants for the following 6 months (Phase I), and subjects will be followed for 6 more months to examine effects following cessation of incentives (Phase II). A total of 188 participants will be randomized into the 3 arms. Specific Aims will be to assess among participants who lose 5kg or more of baseline weight during Pre Phase: (1) the effectiveness of a daily lottery-based financial incentive, relative to the usual care group, on maintenance of weight loss over the ensuing 6 months; (2) the effectiveness of a direct payment incentive relative to the usual care group oh maintenance of weight loss; (3) the comparative effectiveness of lottery based and direct payment financial incentives on maintenance of weight loss at the end of Phase I (month 12). In addition, we will assess the degree to which weight loss is maintained in the intervention groups compared to the usual care group following cessation ofthe interventions, and we will assess the cost-effectiveness of incentives for maintenance of weight loss. This study will build on our successful efforts using lottery-based incentives for weight loss in partnership between experienced teams at the Center for Health Incentives and Behavioral Economics ofthe Leonard Davis Institute of Health Economics (LDI CHIBE) at the University of Pennsylvania and at Duke University. RELEVANCE (See instructions): This study will contribute valuable knowledge about the effectiveness of innovative strategies to improve maintenance of weight loss among middle aged and older Americans. This is central to reducing morbidity and mortality rates among older Americans and improving the health ofthe US population more broadly since obesity is extremely common among Americans. '